This invention relates to processes for separating metals from mixtures thereof.
It is known to separate one metal from a mixture of two or more present in an aqueous medium, eg as soluble salts, by contacting the mixture with a chemical reagent which precipitates the metal of the one salt as an insoluble compound while maintaining the others in a dissolved condition or redissolving any precipitate thereof in an excess of the reagent. However the precipitates formed in such processes are usually amorphous in physical form, eg slimes, which are difficult to separate from the liquid, e.g., by filtration, and subsequently to wash and handle if desired.
The present invention provides a separation process in which the precipitated compound is formed as discrete, separable entities, eg., spherical or irregular particles, but permeable by chemical species in liquid media. The existence of the precipitate in this form and with these properties greatly alleviates the aforementioned difficulties.